From: Tom Lane <tgl@sss.pgh.pa.us>
To: Robert Haas <robertmhaas@gmail.com>
cc: Amul Sul <sulamul@gmail.com>, Sravan Kumar <sravanvcybage@gmail.com>,
        PostgreSQL-development <pgsql-hackers@postgresql.org>
Subject: Re: pg_verifybackup: TAR format backup verification
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Comments: In-reply-to Robert Haas <robertmhaas@gmail.com>
	message dated "Mon, 30 Sep 2024 16:11:58 -0400"
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Date: Mon, 30 Sep 2024 18:05:56 -0400
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Robert Haas <robertmhaas@gmail.com> writes:
> On Mon, Sep 30, 2024 at 11:31 AM Tom Lane <tgl@sss.pgh.pa.us> wrote:
>> WFM, modulo the suggestion about changing data types.

> I would prefer not to make the data type change here because it has
> quite a few tentacles.

I see your point for the function's "len" argument, but perhaps it's
worth doing

-       int            remaining;
+       size_t         remaining;

        remaining = sizeof(ControlFileData) - mystreamer->control_file_bytes;
        memcpy(((char *) &mystreamer->control_file)
               + mystreamer->control_file_bytes,
-              data, Min(len, remaining));
+              data, Min((size_t) len, remaining));

This is enough to ensure the Min() remains safe.

			regards, tom lane